1. Field of the Invention
The present invention relates generally to the field of drive arrangements for electrical switches and interrupters and more particularly to a drive arrangement that provides independent rotary and linear outputs and includes a rotatable support column having an operating member longitudinally disposed therethrough to provide the linear output; rotation of the column providing the rotary output.
2. Description of the Related Art
Various support columns, operating columns, and operating members are known for use with electrical switches, disconnects, interrupters, and the like. These arrangements are normally subjected to line-to-ground voltage. For example, U.S. Pat. No. 3,508,178 discloses a rotatable insulator that is utilized in the switch operator linkage. A sequencing mechanism at the live parts drives both a disconnect blade and an interrupting unit. Another smaller diameter rotatable insulator is utilized in an auxiliary trip arrangement for rapid tripping. Other arrangements utilize a separate reciprocating insulator.
Another similar arrangement disclosed in U.S. Pat. No. 4,110,579 obtains rapid interrupter tripping by a rapid initial rotation of the main rotatable insulator during its operative movement, continued rotation opening a disconnect switch.
Additionally, other drive linkage arrangements include insulator columns sealed with pressurized gas or oil that carry translational operating members driven in various manners, commonly by pivotal linkage members that enter the sealed insulator column through an "O" ring seal or the like. Other arrangements of this type can be categorized as using a crank arrangement with a rotating shaft seal. Another arrangement utilizes a pneumatically-driven operating rod in a circuit-breaker. A typical example of this arrangement is available from AEG under the designation SF7 Auto Pneumatic.
While these arrangements are generally suitable for their intended purpose, these arrangements are not applicable or desirable for all applications and it is advantageous to provide improved drive arrangements that efficiently combine independent rotary and translational operating drives with the translational drive being capable of rapid operation without any external parts exposed to the environment. For example, it is necessary to provide rapid movement for operation of an interrupting unit. Since the drive for this rapid movement is subjected to line-to-ground voltage, the prior arrangements that utilize separate insulators for this movement are limited in speed by the mass of the insulator. Further, as to the prior arrangements that combine the drives, these combined drives are either limited in speed by the mass of the insulator or require a relatively complicated mechanism at line potential for each phase.